Recently, a force applied to each portion of the tire during the running becomes large with the speeding up of a vehicle, and hence it is demanded to prevent the deformation of the tire due to these forces to improve the steering stability. As to this demand, it is considered to thicken a gauge of each portion of the tire. In this case, however, the weight of the tire increases, and there is a problem that a low fuel consumption of the tire is deteriorated.
To the contrary, as a means for improving a stiffness of each portion of the tire without increasing the tire weight, there is known a technique wherein a reinforcing layer composed of each of various fabrics is disposed at a desired reinforcing site. Among these fabrics used in the reinforcing layer, a triaxial fabric is known to be excellent in the action of dispersing the applied force.
For example, there is known a pneumatic tire comprising a steel belt layer disposed at an outside of a carcass in a radial direction of the tire in which a triaxial fabric body is arranged at an outside of the steel belt layer in the radial direction of the tire as a band layer (belt reinforcing layer) by winding once or more in a circumferential direction of the tire. In the tire, a lifting phenomenon of steel cords in the steel belt layer during the high-speed running is suppressed to improve a uniformity of the tire (see JP-A-H04-303002).
Also, it is known that the triaxial fabric is used as a carcass and a bead reinforcing layer of the tire as well as a tensile belt of a rubber crawler to improve durabilities of the tire and the rubber crawler (see JP-A-H03-220338). Furthermore, it is known to improve the steering stability of the tire by disposing a bead reinforcing layer composed of the triaxial fabric in the bead portion (see JP-A-H07-156619). Moreover, it is known that the triaxial fabric is used as the belt of the tire to prevent a pantograph deformation of the belt and improve the durability of the tire (see JP-A-2002-2218).